<?php

defined('BASEPATH') or die('forbidden');

/**
 * 根据IP获取真实地址
 * @author  Karson
 * @name    ip.php
 * @since   2011-3-26 23:57:24
 */
function ipaddress($ip, $charet = 'UTF-8') {
    $ippath = BASEPATH . 'commons/' . 'qqwry.dat';
    if (!preg_match("/^\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}$/", $ip))
        return 'IP错误';

    $iparray = explode('.', $ip);

    if ($iparray[0] == 10 || $iparray[0] == 127 || ($iparray[0] == 192 && $iparray[1] == 168) || ($iparray[0] == 172 && ($iparray[1] >= 16 && $iparray[1] <= 31))) {
        return '本地局域网';
    } elseif ($iparray[0] > 255 || $iparray[1] > 255 || $iparray[2] > 255 || $iparray[3] > 255) {
        return '无效的IP';
    }

    if (!$fd = @fopen($ippath, 'rb'))
        return 'IP数据库读取错误';

    $ip = explode('.', $ip);
    $ipNum = $ip[0] * 16777216 + $ip[1] * 65536 + $ip[2] * 256 + $ip[3];

    if (!($DataBegin = fread($fd, 4)) || !($DataEnd = fread($fd, 4)))
        return;
    @$ipbegin = implode('', unpack('L', $DataBegin));
    if ($ipbegin < 0)
        $ipbegin += pow(2, 32);
    @$ipend = implode('', unpack('L', $DataEnd));
    if ($ipend < 0)
        $ipend += pow(2, 32);
    $ipAllNum = ($ipend - $ipbegin) / 7 + 1;

    $BeginNum = $ip2num = $ip1num = 0;
    $ipAddr1 = $ipAddr2 = '';
    $EndNum = $ipAllNum;

    while ($ip1num > $ipNum || $ip2num < $ipNum) {
        $Middle = intval(($EndNum + $BeginNum) / 2);

        fseek($fd, $ipbegin + 7 * $Middle);
        $ipData1 = fread($fd, 4);
        if (strlen($ipData1) < 4) {
            fclose($fd);
            return 'System Error';
        }
        $ip1num = implode('', unpack('L', $ipData1));
        if ($ip1num < 0)
            $ip1num += pow(2, 32);

        if ($ip1num > $ipNum) {
            $EndNum = $Middle;
            continue;
        }

        $DataSeek = fread($fd, 3);
        if (strlen($DataSeek) < 3) {
            fclose($fd);
            return 'System Error';
        }
        $DataSeek = implode('', unpack('L', $DataSeek . chr(0)));
        fseek($fd, $DataSeek);
        $ipData2 = fread($fd, 4);
        if (strlen($ipData2) < 4) {
            fclose($fd);
            return 'System Error';
        }
        $ip2num = implode('', unpack('L', $ipData2));
        if ($ip2num < 0)
            $ip2num += pow(2, 32);

        if ($ip2num < $ipNum) {
            if ($Middle == $BeginNum) {
                fclose($fd);
                return 'Unknown';
            }
            $BeginNum = $Middle;
        }
    }

    $ipFlag = fread($fd, 1);
    if ($ipFlag == chr(1)) {
        $ipSeek = fread($fd, 3);
        if (strlen($ipSeek) < 3) {
            fclose($fd);
            return 'System Error';
        }
        $ipSeek = implode('', unpack('L', $ipSeek . chr(0)));
        fseek($fd, $ipSeek);
        $ipFlag = fread($fd, 1);
    }

    if ($ipFlag == chr(2)) {
        $AddrSeek = fread($fd, 3);
        if (strlen($AddrSeek) < 3) {
            fclose($fd);
            return 'System Error';
        }
        $ipFlag = fread($fd, 1);
        if ($ipFlag == chr(2)) {
            $AddrSeek2 = fread($fd, 3);
            if (strlen($AddrSeek2) < 3) {
                fclose($fd);
                return 'System Error';
            }
            $AddrSeek2 = implode('', unpack('L', $AddrSeek2 . chr(0)));
            fseek($fd, $AddrSeek2);
        } else {
            fseek($fd, -1, SEEK_CUR);
        }

        while (($char = fread($fd, 1)) != chr(0))
            $ipAddr2 .= $char;

        $AddrSeek = implode('', unpack('L', $AddrSeek . chr(0)));
        fseek($fd, $AddrSeek);

        while (($char = fread($fd, 1)) != chr(0))
            $ipAddr1 .= $char;
    } else {
        fseek($fd, -1, SEEK_CUR);
        while (($char = fread($fd, 1)) != chr(0))
            $ipAddr1 .= $char;

        $ipFlag = fread($fd, 1);
        if ($ipFlag == chr(2)) {
            $AddrSeek2 = fread($fd, 3);
            if (strlen($AddrSeek2) < 3) {
                fclose($fd);
                return 'System Error';
            }
            $AddrSeek2 = implode('', unpack('L', $AddrSeek2 . chr(0)));
            fseek($fd, $AddrSeek2);
        } else {
            fseek($fd, -1, SEEK_CUR);
        }
        while (($char = fread($fd, 1)) != chr(0))
            $ipAddr2 .= $char;
    }
    fclose($fd);

    if (preg_match('/http/i', $ipAddr2))
        $ipAddr2 = '';
    $ipaddr = "$ipAddr1  $ipAddr2";
    $ipaddr = preg_replace('/CZ88\.NET/is', '', $ipaddr);
    $ipaddr = preg_replace('/^\s*/is', '', $ipaddr);
    $ipaddr = preg_replace('/\s*$/is', '', $ipaddr);
    if (preg_match('/http/i', $ipaddr) || $ipaddr == '')
        $ipaddr = 'Unknown';
    $ipaddr = ($charet != 'GBK') ? iconv('GBK', $charet, $ipaddr) : $ipaddr;
    return $ipaddr;
}